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Abstract:

A method includes receiving during a first time interval image data
associated with an image of a dynamic body. The image data includes an
indication of the positions of a first marker and a second marker on a
garment coupled to the dynamic body. The first marker and second marker
are each coupled to the garment at a first and second locations,
respectively. A distance is determined between the position of the first
marker and the second marker. During a second time interval after the
first time interval, data associated with a position of a first and
second localization element that are each coupled to the garment is
received. A distance between the first and second localization elements
is determined. A difference is calculated between the distance between
the first marker and the second marker and the distance between the first
localization element and the second localization element.

Claims:

1. A method, comprising: receiving during a first time interval image
data associated with a path of motion of a dynamic body, the image data
including a plurality of images each indicating a position of a first
marker on a garment coupled to the dynamic body and a position of a
second marker on the garment coupled to the dynamic body for an instant
in time throughout the path of motion of the dynamic body, the first
marker being coupled to the garment at a first location, the second
marker being coupled to the garment at a second location; determining a
vector distance between the position of the first marker and the position
of the second marker in three-dimensional space based on the position of
the first marker and the position of the second marker for each instant
of time; receiving during a second time interval after the first time
interval data associated with a position in three-dimensional space of a
first localization element coupled to the garment at the first location
and data associated with a position in three-dimensional space of a
second localization element coupled to the garment at the second
location; determining a vector distance between the position of the first
localization element and the position of the second localization element
based on the data associated with the position of the first localization
element and the position of the second localization element; and
identifying from the determined vector distances between the position of
the first marker and the position of the second marker a vector distance
between the position of the first marker and the position of the second
marker that is substantially the same as the vector distance between the
position of the first localization element and the position of the second
localization element.

2. The method of claim 1, wherein the garment has a sleeve configuration.

3. The method of claim 1, wherein the receiving image data includes
receiving image data from a computed tomography device.

6. The method of claim 1, further comprising: receiving the data
associated with a position of the first localization element and the data
associated with a position of the second localization element
continuously during the second time interval and recording the data
associated with a position of the first localization element and the data
associated with a position of the second localization element
continuously during the second time interval.

7. The method of claim 1, wherein the plurality of images each further
indicate a position in three-dimensional space of a third marker on the
garment and a position in three-dimensional space of a fourth marker on
the garment for an instant in time throughout the path of motion of the
dynamic body, the third marker coupled to the garment at a third location
and the fourth marker coupled to the garment at a fourth location;
determining a vector distance between the position of the third marker
and the position of the fourth marker based on the position of the third
marker and the position of the fourth marker; receiving during the second
time interval data associated with a position in three-dimensional space
of a third localization element coupled to the garment at the third
location and data associated with a position in three-dimensional space
of a fourth localization element coupled to the garment at the fourth
location; determining a vector distance between the position of the third
localization element and the position of the fourth localization element
based on the data associated with the position of the third localization
element and the position of the second localization element; and
identifying from the determined vector distances between the third marker
and the fourth marker a vector distance between the position of the third
marker and the position of the fourth marker that is substantially the
same as the vector distance between the position of the third
localization element and the position of the fourth localization element.

8. The method of claim 1, wherein the garment is configured to at least
partially constrict movement of the dynamic body.

9. The method of claim 1, further comprising: selecting an image based on
the identified vector distance.

10. An apparatus, comprising: a first marker coupled to a garment at a
first location, a second marker coupled to the garment at a second
location, the garment being substantially planar and configured to be
adhesively coupled to a dynamic body; a first element coupled to the
garment proximate the location of the first marker; and a second element
coupled to the garment proximate the location of the second marker, the
first element and the second element each being coupled to a receiving
device and configured to simultaneously send to the receiving device
position data associated with a plurality of positions in
three-dimensional space of the first element and position data associated
with a plurality of positions in three-dimensional space of the second
element during a path of motion of the dynamic body, wherein the
receiving device determines a vector distance between the position of the
first element and the position of the second element based on the
position data for each instant of time for a plurality of instants of
time during the motion of the dynamic body.

11. The apparatus of claim 10, wherein the first marker and the second
marker are each radio-opaque markers.

12. The apparatus of claim 10, wherein the first element and the second
element are each one of electromagnetic coils, optical infrared light
emitting diodes, optical passive reflective markers, or voltage induced
coils.

13. The apparatus of claim 10, wherein the garment is configured to be
coupled to the upper torso of a patient.

14. A processor-readable medium storing code representing instructions to
cause a processor to perform a process, the code comprising code to:
receive during a first time interval image data associated with a path of
motion in three-dimensional space of a dynamic body; receive during the
first time interval position data based on the image data received, the
position data indicating position in three-dimensional space of a first
marker on a garment coupled to the dynamic body and a position in
three-dimensional space of a second marker on the garment coupled to the
dynamic body for a plurality of instants of time during the first time
interval, the first marker being coupled to the garment at a first
location, the second marker being coupled to the garment at a second
location; determine a vector distance between the position of the first
marker and the position of the second marker based on the position data
for each instant of time from the plurality of instants of time during
the first interval; receive during a second time interval after the first
time interval data associated with a position in three-dimensional space
of a first localization element coupled to the garment at the first
location and data associated with a position in three-dimensional space
of a second localization element coupled to the garment at the second
location; determine a vector distance between the first localization
element and the second localization element based on the data associated
with the position of the first localization element and the position of
the second localization element; and identify from the determined vector
distances between the position of the first marker and the position of
the second marker a vector distance between the position of the first
marker and the position of the second marker that is substantially the
same as the vector distance between the first localization element and
the second localization element.

17. The processor-readable medium of claim 14, the code further
comprising code to: record the data received associated with a position
of the first localization element and record the data received associated
with a position of the second localization element.

18. The processor-readable medium of claim 14, the code further
comprising code to: receive the data associated with a position of the
first localization element and the data associated with a position of the
second localization element continuously during the second time interval;
and record the data associated with a position of the first localization
element and the data associated with a position of the second
localization element continuously during the second time interval.

19. The processor-readable medium of claim 14, wherein the identifying
includes executing an algorithm configured to compare the determined
vector distances associated with the first marker and the second marker
to the vector distance associated with the first localization element and
the second localization element.

20. The processor-readable medium of claim 19, further comprising code
to: receive during the first time interval position data indicating a
position in three-dimensional space of a third marker on the garment and
a position in three-dimensional space of a fourth marker on the garment
for a plurality of instants of time during the first time interval, the
third marker coupled to the garment at a third location and the fourth
marker coupled to the garment at a fourth location; determine a vector
distance between the position of the third marker and the position of the
fourth marker; receive during the second time interval data associated
with a position in three-dimensional space of a third localization
element coupled to the garment at the third location and data associated
with a position in three-dimensional space of a fourth localization
element coupled to the garment at the fourth location; determine a vector
distance between the third localization element and the fourth
localization element based on the data associated with the position of
the third localization element and the position of the second
localization element; and identify from the determined vector distances
between the position of the third marker and the position of the fourth
marker a vector distance between the position of the third marker and the
position of the fourth marker that is substantially the same as the
vector distance between the position of the third localization element
and the position of the fourth localization element.

Description:

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation of U.S. patent application Ser.
No. 11/224,028, filed on Sep. 13, 2005, which is incorporated herein by
reference.

BACKGROUND

[0002] The invention relates generally to a medical device and
particularly to an apparatus and method associated with image guided
medical procedures.

[0003] Image guided surgery (IGS), also known as image guided intervention
(IGI), enhances a physician's ability to locate instruments within
anatomy during a medical procedure. IGS can include 2-dimensional (2-D)
and 3-dimensional (3-D) applications.

[0004] Existing imaging modalities can capture the movement of dynamic
anatomy. Such modalities include electrocardiogram (ECG)-gated or
respiratory-gated magnetic resonance imaging (MRI) devices, ECG-gated or
respiratory-gated computer tomography (CT) devices, and cinematography
(CINE) fluoroscopy. The dynamic imaging modalities can capture the
movement of anatomy over a periodic cycle of that movement by sampling
the anatomy at several instants during its characteristic movement and
then creating a set of image frames or volumes.

[0005] A need exists for an apparatus that can be used with such imaging
devices to capture pre-procedural images of a targeted anatomical body
and use those images intra-procedurally to help guide a physician to the
correct location of the anatomical body during a medical procedure.

SUMMARY OF THE INVENTION

[0006] A method includes receiving during a first time interval image data
associated with an image of a dynamic body. The image data includes an
indication of a position of a first marker on a garment coupled to the
dynamic body and a position of a second marker on the garment. The first
marker is coupled to the garment at a first location. The second marker
is coupled to the garment at a second location. A distance between the
position of the first marker and the position of the second marker is
determined. During a second time interval after the first time interval,
data associated with a position of a first localization element coupled
to the garment at the first location and data associated with a position
of a second localization element coupled to the garment at the second
location are received. A distance between the first localization element
and the second localization element based on the data associated with the
position of the first localization element and the position of the second
localization element is determined. A difference is calculated between
the distance between the first marker and the second marker during the
first time interval and the distance between the first localization
element and the second localization element during the second time
interval.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The present invention is described with reference to the
accompanying drawings.

[0008] FIG. 1 is a schematic illustration of various devices used with a
method according to an embodiment of the invention.

[0009] FIG. 2 is a schematic illustration of various devices used with a
method according to an embodiment of the invention.

[0010] FIG. 3 is a schematic illustrating vector distances on an apparatus
according to an embodiment of the invention.

[0011] FIG. 4A is a schematic illustrating vector distances from a
localization device according to an embodiment of the invention.

[0012] FIG. 4B is a schematic illustrating vector distances from image
data according to an embodiment of the invention.

[0013] FIG. 5 is a front perspective view of an apparatus according to an
embodiment of the invention.

[0014] FIG. 6 is a graphical representation illustrating the function of
an apparatus according to an embodiment of the invention.

[0015] FIG. 7 is a flowchart illustrating a method according to an
embodiment of the invention.

DETAILED DESCRIPTION

[0016] An apparatus according to an embodiment of the invention includes a
garment and two or more markers coupled to the garment. The apparatus can
also include two or more localization elements coupled to the garment
proximate the markers. The apparatus is configured to be coupled to a
dynamic body, such as selected dynamic anatomy of a patient. Dynamic
anatomy can be, for example, any anatomy that moves during its normal
function (e.g., the heart, lungs, kidneys, liver and blood vessels). A
processor, such as a computer, is configured to receive image data
associated with the dynamic body taken during a pre-surgical or
pre-procedural first time interval. The image data can include an
indication of a position of each of the markers for multiple instants in
time during the first time interval. The processor can also receive
position data associated with the localization elements during a second
time interval in which a surgical procedure or other medical procedure is
being performed. The processor can use the position data received from
the localization elements to determine a distance between the elements
for a given instant in time during the second time interval. The
processor can also use the image data to determine the distance between
the markers for a given instant in time during the first time interval.
The processor can then find a match between an image where the distance
between the markers at a given instant in time during the first time
interval is the same as the distance between the elements associated with
those markers at a given instant in time during the medical procedure, or
second time interval.

[0017] A physician or other healthcare professional can use the images
selected by the processor during a medical procedure performed during the
second time interval. For example, when a medical procedure is performed
on a targeted anatomy of a patient, such as a heart, the physician may
not be able to utilize an imaging device during the medical procedure to
guide him to the targeted area within the patient. A garment according to
an embodiment of the invention can be positioned or coupled to the
patient proximate the targeted anatomy prior to the medical procedure,
and pre-procedural images can be taken of the targeted area during a
first time interval. Markers or fiducials coupled to the garment can be
viewed with the image data, which can include an indication of the
position of the markers during a given path of motion of the targeted
anatomy (e.g., the heart) during the first time interval. Such motion can
be due, for example, to inspiration (i.e., inhaling) and expiration
(i.e., exhaling) of the patient, or due to the heart beating. During a
medical procedure, performed during a second time interval, such as a
procedure on a heart, the processor receives data from the localization
elements associated with a position of the elements at a given instant in
time during the medical procedure (or second time interval). The distance
between selected pairs of markers can be determined from the image data
and the distance between corresponding selected pairs of localization
elements can be determined based on the element data for given instants
in time.

[0018] Because the localization elements are coupled to the garment
proximate the location of the markers, the distance between a selected
pair of elements can be used to determine an intra-procedural distance
between the pair of corresponding markers to which the localization
elements are coupled. An image from the pre-procedural image data taken
during the first time interval can then be selected where the distance
between the pair of selected markers in that image corresponds with or
closely approximates the same distance determined using the localization
elements at a given instant in time during the second time interval. This
process can be done continuously during the medical procedure, producing
simulated real-time, intra-procedural images illustrating the orientation
and shape of the targeted anatomy as a catheter or similar structure is
navigated to the targeted anatomy. Thus, during the medical procedure,
the physician can view selected image(s) of the targeted anatomy that
correspond to and simulate real-time movement of the anatomy. In
addition, during a medical procedure being performed during the second
time interval, such as navigating a catheter to a targeted anatomy, the
location(s) of an electromagnetic coil coupled to the catheter during the
second time interval can be superimposed on an image of a catheter. The
superimposed image(s) of the catheter can then be superimposed on the
selected image(s) from the first time interval, providing simulated real
time images of the catheter location relative to the targeted anatomy.
This process and other related methods are described in pending U.S.
patent application Ser. No. 10/273,598, entitled Methods, Apparatuses,
and Systems Useful in Conducting Image Guided Interventions, filed Nov.
8, 2003, the entire disclosure of which is incorporated herein by
reference.

[0019] FIGS. 1 and 2 are schematic illustrations of devices that can be
used to perform various procedures described herein. As shown in FIG. 1,
an apparatus 10 includes a garment 20. The garment 20 can be coupled to a
dynamic body B. The dynamic body B can be, for example, a selected
dynamic portion of the anatomy of a patient. The garment 20 can be a
variety of different shapes and sizes. For example, in one embodiment the
garment 20 is a tubular or sleeve configuration (see FIG. 5) and can fit,
for example, around the torso of a patient, or around the upper chest
surrounding, for example, the patient's heart. The garment 20 can be a
continuous tubular configuration or a partial tubular configuration. For
example, the garment 20 may be substantially planar prior to coupling to
the dynamic body and then wrapped around the dynamic body and coupled to
the dynamic body using an attachment, such as straps, hook and pile
fastener, snaps, or any other suitable coupling method. In the case of a
continuous tubular shape, the garment 20 may be held in position on the
dynamic body through friction fit, or due to the garment being
stretchable such that it conforms to the dynamic body. In another
embodiment, the garment 20 is substantially planar, such as in the form
of a patch that can be disposed at a variety of locations on a patient's
body. Such a garment 20 can be coupled to the dynamic body with adhesive,
straps, hook and pile, snaps, or any other suitable coupling method.

[0020] In some embodiments, the garment 20 is configured as a shirt to be
worn by a patient. In some embodiments, the garment 20 is configured to
be worn similar to a pair of pants. In still other embodiments, a garment
is configured as an undergarment to be worn by a patient. For example, a
garment can be configured as an undergarment to be worn on the upper
torso of the patient (e.g., a brassiere). These configurations may allow,
for example, placement of markers at varying angles relative to the
targeted anatomy of the patient.

[0021] The garment 20 can be constructed with a variety of different
materials, such as fabric, plastic, and rubber and can be flexible,
stretchable and/or rigid. In some embodiments, the garment 20 is
configured to constrict movement of the dynamic body B. For example, the
garment 20 can be constructed in a tubular configuration with a
stretchable material that when coupled to the patient's body, constricts
at least a portion of the patient's movement through inhaling and
exhaling or movement caused by the heart beating.

[0022] Two or more markers or fiducials 22 are coupled to the garment 20
at selected locations as shown in FIG. 1. The markers 22 are constructed
of a material that can be viewed on an image, such as an X-ray. The
markers 22 can be, for example, radiopaque, and can be coupled to the
garment 20 using any known methods of coupling such devices. FIGS. 1 and
2 illustrate the apparatus 10 having four markers 22, but any number of
two or more markers can be used.

[0023] An imaging device 40 can be used to take images of the dynamic body
B while the garment 20 is coupled to the dynamic body B, pre-procedurally
during a first time interval. As stated above, the markers 22 are visible
on the images and can provide an indication of a position of each of the
markers 22 during the first time interval. The position of the markers 22
at given instants in time through a path of motion of the dynamic body B
can be illustrated with the images. The imaging device 40 can be, for
example, a computed tomography (CT) device (e.g., respiratory-gated CT
device, ECG-gated CT device), a magnetic resonance imaging (MRI) device
(e.g., respiratory-gated MRI device, ECG-gated MRI device), an X-ray
device, or any other suitable medical imaging device. In one embodiment,
the imaging device 40 is a computed tomography-positron emission
tomography device that produces a fused computed tomography-positron
emission tomography image dataset. The imaging device 40 can be in
communication with a processor 30 and send, transfer, copy and/or provide
image data taken during the first time interval associated with the
dynamic body B to the processor 30.

[0024] The processor 30 includes a processor-readable medium storing code
representing instructions to cause the processor 30 to perform a process.
The processor 30 can be, for example, a commercially available personal
computer, or a less complex computing or processing device that is
dedicated to performing one or more specific tasks. For example, the
processor 30 can be a terminal dedicated to providing an interactive
graphical user interface (GUI). The processor 30, according to one or
more embodiments of the invention, can be a commercially available
microprocessor. Alternatively, the processor 30 can be an
application-specific integrated circuit (ASIC) or a combination of ASICs,
which are designed to achieve one or more specific functions, or enable
one or more specific devices or applications. In yet another embodiment,
the processor 30 can be an analog or digital circuit, or a combination of
multiple circuits.

[0025] The processor 30 can include a memory component 32. The memory
component 32 can include one or more types of memory. For example, the
memory component 32 can include a read only memory (ROM) component and a
random access memory (RAM) component. The memory component can also
include other types of memory that are suitable for storing data in a
form retrievable by the processor 30. For example, electronically
programmable read only memory (EPROM), erasable electronically
programmable read only memory (EEPROM), flash memory, as well as other
suitable forms of memory can be included within the memory component. The
processor 30 can also include a variety of other components, such as for
example, co-processors, graphic processors, etc., depending upon the
desired functionality of the code.

[0026] The processor 30 can store data in the memory component 32 or
retrieve data previously stored in the memory component 32. The
components of the processor 30 can communicate with devices external to
the processor 30 by way of an input/output (I/O) component (not shown).
According to one or more embodiments of the invention, the I/O component
can include a variety of suitable communication interfaces. For example,
the I/O component can include, for example, wired connections, such as
standard serial ports, parallel ports, universal serial bus (USB) ports,
S-video ports, local area network (LAN) ports, small computer system
interface (SCCI) ports, and so forth. Additionally, the I/O component can
include, for example, wireless connections, such as infrared ports,
optical ports, Bluetooth® wireless ports, wireless LAN ports, or the
like.

[0027] The processor 30 can be connected to a network, which may be any
form of interconnecting network including an intranet, such as a local or
wide area network, or an extranet, such as the World Wide Web or the
Internet. The network can be physically implemented on a wireless or
wired network, on leased or dedicated lines, including a virtual private
network (VPN).

[0028] As stated above, the processor 30 can receive image data from the
imaging device 40. The processor 30 can identify the position of selected
markers 22 within the image data or voxel space using various
segmentation techniques, such as Hounsfield unit thresholding,
convolution, connected component, or other combinatory image processing
and segmentation techniques. The processor 30 can determine a distance
and direction between the position of any two markers 22 during multiple
instants in time during the first time interval, and store the image
data, as well as the position and distance data, within the memory
component 32. Multiple images can be produced providing a visual image at
multiple instants in time through the path of motion of the dynamic body.
The processor 30 can also include a receiving device or localization
device 34, which is described in more detail below.

[0029] As shown in FIG. 2, two or more localization elements 24 are
coupled to the garment 20 proximate the locations of the markers 22 for
use during a medical procedure to be performed during a second time
interval. The localization elements 24 can be, for example,
electromagnetic coils, infrared light emitting diodes, and/or optical
passive reflective markers. The markers 22 can include plastic or
non-ferrous fixtures or dovetails or other suitable connectors used to
couple the localization elements 24 to the markers 22. A medical
procedure can then be performed with the garment 20 coupled to the
dynamic body B at the same location as during the first time interval
when the pre-procedural images were taken. During the medical procedure,
the localization elements 24 are in communication or coupled to the
localization device 34 included within processor 30. The localization
device 34 can be, for example, an analog to digital converter that
measures voltages induced onto localization coils in the field; creates a
digital voltage reading; and maps that voltage reading to a metric
positional measurement based on a characterized volume of voltages to
millimeters from a fixed field emitter. Position data associated with the
elements 24 can be transmitted or sent to the localization device 34
continuously during the medical procedure during the second time
interval. Thus, the position of the localization elements 24 can be
captured at given instants in time during the second time interval.
Because the localization elements 24 are coupled to the garment 20
proximate the markers 22, the localization device 34 can use the position
data of the elements 24 to deduce coordinates or positions associated
with the markers 22 intra-procedurally during the second time interval.
The distance between one or more selected pairs of localization elements
24 (and corresponding markers 22) can then be determined and various
algorithms can be used to analyze and compare the distance between
selected elements 24 at given instants in time, to the distances between
and orientation among corresponding markers 22 observed in the
pre-operative images.

[0030] An image can then be selected from the pre-operative images taken
during the first time interval that indicates a distance between
corresponding markers 22 at a given instant in time, that most closely
approximates or matches the distance between the selected elements 24.
The process of comparing the distances is described in more detail below.
Thus, the apparatus 10 and processor 30 can be used to provide images
corresponding to the actual movement of the targeted anatomy during the
medical procedure being performed during the second time interval. The
images illustrate the orientation and shape of the targeted anatomy
during a path of motion of the anatomy, for example, during inhaling and
exhaling.

[0031] FIG. 3 illustrates an example set of distances or vectors d1
through d6 between a set of markers 122, labeled m1 through m9 that are
disposed at spaced locations on a garment 120. As described above,
pre-procedure images can be taken of a dynamic body for which the garment
120 is to be coupled during a first time interval. The distances between
the markers can be determined for multiple instants in time through the
path of motion of the dynamic body. Then, during a medical procedure,
performed during a second time interval, localization elements (not shown
in FIG. 3) coupled proximate to the location of markers 122 can provide
position data for the elements to a localization device (not shown in
FIG. 3). The localization device can use the position data to determine
distances or vectors between the elements for multiple instants in time
during the medical procedure or second time interval.

[0032] FIG. 4A shows an example of distance or vector data from the
localization device. Vectors a1 through a6 represent distance data for
one instant in time and vectors n1 through n6 for another instant in
time, during a time interval from a to n. As previously described, the
vector data can be used to select an image from the pre-procedural images
that includes distances between the markers m1 through m9 that correspond
to or closely approximate the distances a1 through a6 for time a, for
example, between the localization elements. The same process can be
performed for the vectors n1 through n6 captured during time n.

[0033] One method of selecting the appropriate image from the
pre-procedural images is to execute an algorithm that can sum all of the
distances a1 through a6 and then search for and match this sum to an
image containing a sum of all of the distances d1 through d6 obtained
pre-procedurally from the image data that is equal to the sum of the
distances a1 through a6. When the difference between these sums is equal
to zero, the relative position and orientation of the anatomy or dynamic
body D during the medical procedure will substantially match the position
and orientation of the anatomy in the particular image. The image
associated with distances d1 through d6 that match or closely approximate
the distances a1 through a6 can then be selected and displayed. For
example, FIG. 4B illustrates examples of pre-procedural images, Image a
and Image n, of a dynamic body D that correspond to the distances a1
through a6 and n1 through n6, respectively. An example of an algorithm
for determining a match is as follows:

[0034] Does Σ
ai=Σ di (i=1 to 6 in this example) OR

[0035] Does Σ
(ai-di)=0 (i=1 to 6 in this example).

[0036] If yes to either of these, then the image is a match to the vector
or distance data obtained during the medical procedure.

[0037] FIG. 5 illustrates an apparatus 210 according to an embodiment of
the invention. The apparatus 210 includes a tubular shaped garment 220
that can be constructed with a flexible and/or stretchable material. The
garment 220 can be positioned over a portion of a patient's body, such as
around the upper or lower torso of the patient. The stretchability of the
garment 220 allows the garment 220 to at least partially constrict some
of the movement of the portion of the body for which it is coupled. The
apparatus 210 further includes multiple markers or fiducials 222 coupled
to the garment 220 at spaced locations. A plurality of localization
elements 224 are removably coupled proximate to the locations of markers
222, such that during a first time interval as described above, images
can be taken without the elements 224 being coupled to the garment 220.
The localization elements need not be removably coupled. For example, the
elements can be fixedly coupled to the garment. In addition, the elements
can be coupled to the garment during the pre-procedure imaging.

[0038] FIG. 6 is a graphical illustration indicating how the apparatus 210
(shown without localization elements 224) can move and change orientation
and shape during movement of a dynamic body, such as a mammalian body M.
The graph is one example of how the lung volume can change during
inhalation (inspiration) and exhalation (expiration) of the mammalian
body M. The corresponding changes in shape and orientation of the
apparatus 210 during inhalation and exhalation are also illustrated. The
six markers 222 shown in FIG. 5 are labeled a, b, c, d, e, and f. As
described above, images of the apparatus 110 can be taken during a first
time interval. The images can include an indication of relative position
of each of the markers 222, that is the markers 222 are visible in the
images, and the position of each marker 222 can then be observed over a
period of time. A distance between any two markers 222 can then be
determined for any given instant of time during the first time interval.
For example, a distance X between markers a and b is illustrated, and a
distance Y between markers b and f is illustrated. These distances can be
determined for any given instant in time during the first time interval
from an associated image that illustrates the position and orientation of
the markers 222. As illustrated, during expiration of the mammalian body
M at times indicated as A and C, the distance X is smaller than during
inspiration of the mammalian body M, at the time indicated as B.
Likewise, the distance Y is greater during inspiration than during
expiration. The distance between any pair of markers 222 can be
determined and used in the processes described herein. Thus, the above
embodiments are merely examples of possible pair selections. For example,
a distance between a position of marker e and a position of marker b may
be determined. In addition, multiple pairs or only one pair may be
selected for a given procedure.

[0039] FIG. 7 is a flowchart illustrating a method according to an
embodiment of the invention. A method 50 includes at step 52 receiving
image data during a pre-procedural or first time interval. As discussed
above, images are taken of a dynamic body using an appropriate imaging
modality (e.g., CT Scan, MRI, etc.). The image data is associated with
one or more images taken of a garment (as described herein) coupled to a
dynamic body, where the garment includes two or more markers coupled
thereto. In other words, the image data of the dynamic body is correlated
with image data related to the garment. The one or more images can be
taken using a variety of different imaging modalities as described
previously. The image data can include an indication of a position of a
first marker and an indication of a position of a second marker, as
illustrated at step 54. The image data can include position data for
multiple positions of the markers during a range or path of motion of the
dynamic body over a selected time interval. As described above, the image
data can include position data associated with multiple markers, however,
only two are described here for simplicity. A distance between the
position of the first marker and the position of the second marker can be
determined for multiple instants in time during the first time interval,
at step 56. As also described above, the determination can include
determining the distance based on the observable distance between the
markers on a given image. The image data, including all of the images
received during the first time interval, the position, and the distance
data can be stored in a memory and/or recorded at step 58.

[0040] Then at step 60, during a second time interval, while performing a
medical procedure on the patient with the garment positioned on the
patient at substantially the same location, position data can be received
for a first localization element and a second localization element. The
localization elements can be coupled to the garment proximate the
locations of the markers, such that the position data associated with the
elements can be used to determine the relative position of the markers in
real-time during the medical procedure. The position data of the elements
can be stored and/or recorded at step 62.

[0041] A distance between the first and second localization elements can
be determined at step 64. Although only two localization elements are
described, as with the markers, position data associated with more than
two localization elements can be received and the distances between the
additional elements can be determined.

[0042] The next step is to determine which image from the one or more
images taken during the first time interval represents the relative
position and/or orientation of the dynamic body at a given instant in
time during the second time interval or during the medical procedure. To
determine this, at step 66, the distance between the positions of the
first and second localization elements at a given instant in time during
the second time interval are compared to the distance(s) determined in
step 56 between the positions of the first and second markers obtained
with the image data during the first time interval.

[0043] An image can be selected from the first time interval that best
represents the same position and orientation of the dynamic body at a
given instant in time during the medical procedure. To do this, the
difference between the distance between a given pair of localization
elements during the second time interval is used to select the image that
contains the same distance between the same given pair of markers from
the image data received during the first time interval. This can be
accomplished, for example, by executing an algorithm to perform the
calculations. When there are multiple pairs of markers and localization
elements, the algorithm can sum the distances between all of the selected
pairs of elements for a given instant in time during the second time
interval and sum the distances between all of the associated selected
pairs of markers for each instant in time during the first time interval
when the pre-procedural image data was received.

[0044] When an image is found that provides the sum of distances for the
selected pairs of markers that is substantially the same as the sum of
the distances between the localization elements during the second time
interval, then that image is selected at step 68. The selected image can
then be displayed at step 70. The physician can then observe the image
during the medical procedure on a targeted portion of the dynamic body.
Thus, during the medical procedure, the above process can be continuously
executed such that multiple images are displayed and images corresponding
to real-time positions of the dynamic body can be viewed.

[0045] While various embodiments of the invention have been described
above, it should be understood that they have been presented by way of
example only, and not limitation. Thus, the breadth and scope of the
invention should not be limited by any of the above-described
embodiments, but should be defined only in accordance with the following
claims and their equivalents.

[0046] The previous description of the embodiments is provided to enable
any person skilled in the art to make or use the invention. While the
invention has been particularly shown and described with reference to
embodiments thereof, it will be understood by those skilled in art that
various changes in form and details may be made therein without departing
from the spirit and scope of the invention. For example, the garment,
markers and localization elements can be constructed from any suitable
material, and can be a variety of different shapes and sizes, not
necessarily specifically illustrated, while still remaining within the
scope of the invention.